Antidepressant-Like Effect of Essential Oils From Citrus reticulata in Reserpine-Induced Depressive Mouse

Abstract Citrus reticulata, has been used for various diseases such as cough. According to previous studies, the essential oil of C. reticulata (CREOs) have been shown to be effectively alleviate depression-like behaviors in mice. This study is aimed to investigate the antidepressant-like effect of CREOs in the rapid reserpine-induced depression model mice as well as its possible mechanisms. The experiment was conducted in six groups, each with four mice. The essential oil group and the control group were administered by sniffing (1h/d), while the reserpine group and fluoxetine group by intraperitoneal injection. Body weight, forced swimming test (FST) and tail suspension test (TST) were used to assess depressive behavior. The compositions and contents of CREOs were analyzed by GC-MS. The results indicated that reserpine could reduce the weight of mice and prolong the immobility time of FST and TST. Moreover, the level of 5HT-1A, GR and Nissl bodies in the brain tissue were significantly reduced, while the level of BDNF was increased in reserpine-treated mice. The administration of CREOs could effectively inhibit the weight loss and the prolongation of immobility time caused by reserpine. In addition, the treatment of CREOs has also been shown to reverse the changes in Nissl body, 5-HT, GR and BDNF levels. Limonene was the main active component of CREOs and might be related to the reduction of BDNF. By up-regulating the level of BDNF, CREOs could regulate the hyperexcitability of the HPA axis, thereby increasing the level of neurotransmitters and restoring neurons.